Computer systems commonly comprise a plurality of intercommunicating application programs such as client and server application programs. A client application program may invoke processing on a server application program and typically receives any processing error or failure indications via exceptions generated by the server application program. The server application program generates a predetermined set of exceptions and commonly each such exception is specific to a particular error or failure. Thus client application programs are arranged to identify and process each exception appropriately in accordance with the server application program error or failure represented.
One problem with this arrangement occurs when the server application program is updated for example, to fix problems or for a new version release. The updated server application program may comprise a modified or extended set of exceptions to provide for removed or additional error conditions. However any client application program code that was complied against a previous version of the server application program may not be capable of identifying or processing such new exceptions. This can lead to processing errors in older versions of client application programs when new exceptions are received that cannot be appropriately processed.